Whenever I used to do job concepts, I would always classify jobs by role (tank/melee/ranged/caster/heal), but also whether it was an assault-type job (focused more on damage and whatever its main role was) or support-type (provided more group utility effects). For example, Warrior would've been an assault-type tank because all it really had at the time was tanking ability and damage, while a job like Ninja would've been a support-type melee because it came with Trick Attack and the pair of enmity tools. Ultimately, it all boiled down to what a job brought to the table that wasn't damage.

Nowadays, I think of the assault/support factor as a scale from one to five, with one being more on the support side and five being more focused toward damage (and whatever its assigned primary role is). Again, it just boils down to what a job provides that isn't just damage. It might seem more absurd to tryhards with their eyes glued to their parses, but there is still a benefit to having a clutch Verraise or that one good damage buff that makes those numbers better.